The present invention relates to an injection plug for injecting a repairing agent into a concrete wall for its remedial purpose.
Degradation of concrete material of a concrete construction has been brought to attention. The degradation may be caused through various reasons. The degradation of the concrete may incur separation of a furring mortar formed over the concrete body. Such separation leads to falling of the skin members of a building, which may cause fatal accident for passersby. Accordingly, a proposal for a concrete wall repairing method is becoming a socially urgent matter.
The present inventors have proposed a novel method for injecting a concrete repairing agent, in which double concrete cutters are used for forming a circular injection groove having an approximately constant width, and a concrete repairing agent injection plug which practices the method. These proposals have been described in a copending U.S. patent application Ser. No. 07/714,943 filed Jun. 13, 1991.
The concrete repairing agent injection plug disclosed in the copending application is very effective when used to practice the above described injection method. However, the device has a packing surface which is depressed onto an outer wall surface portion surrounding the injection groove, and the packing is sealingly fixed at the portion for closing an opening end of the injection groove. The device may incur the following disadvantages:
When setting the injection plug over a coarse outer surface which is provided by spraying a mixture of coarse sands and a paint, it is necessary to enhance fluid-tightness between the packing surface and the outer wall surface, at which the open end of the injection groove is positioned. To this effect, the outer surface must be subjected to machining with an electric disc grinder or the like so as to provide a smooth surface of the outer wall in order to provide intimate contact between the wall surface and the packing surface.
If the injection plug is to be set on a locally irregular surface of the outer wall such as a joint lines of the tiles, it would be impossible to provide sufficient fluid tightness between the packing and the outer surface.
It would be rather difficult to fix the injection plug over a curved outer wall surface due to the configuration of the packing.
Residual injection material may be adhered and fixed at an inner wall surface of the injection plug and the packing. Thus, it would be troublesome to remove the residual injection material therefrom.
The residual material may be solidify at an injection nipple and close a fluid passage defined in the injection plug device. The removal work may be troublesome. Particularly, if a check valve is provided within the fluid passage, it would be very difficult to remove the solidified residual material therefrom.